As shown in a system diagram of FIG. 10, a conventional video conference systems includes a terminal apparatus with a function to connect to WAN, for example. The terminal apparatus transfers audio data and image data to a server via the IP network or the ISDN network or the like by use of H323/H320, which is a VoIP protocol, then the server relays video to each terminal apparatus and transmit the audio data to each terminal apparatus.
In particular, recently, performances and functions of portable communication terminals such as camera mounted cellular phones have been improved substantially. For example, a technique for conference participants to perform a multi-point video call by using such a compact mobile terminal is disclosed in Japanese Patent Laid-Open Application No. 2002-335502. Each participant can perform a multi-point video conference at a separate place by applying such technique.